Improvement in screw-cutting machines



- initedtatrs VEDWARD KAYLOR, or PITTSBURG, PENNSYLVANIA.

Letters Patent No. 108,592, daterfA/ugust 23, 1870.

*GOO- IMPROVEMENT SCREW-CUTTING MACHINES.

The Schedule referred to m these l[letters Patent and making part of the same.

l'o all whom t may concern Be itknown that I, EDWARD Karton, of Pitts burg, in the county of Allegheny and State of Pennsylvania, have iuventeda new-and useful Improvement in Screw-cutting Machines; and I do hereby declare the following to be a full, clear, and exact vdescription thercoreferencc beinghad tothe accompanying drawing, in t-wo sheets,- makinor part ot' this specification, in whiclx- Figure 1 is a perspective representation of m yimproved screw-cutting machine, with the parts in working operation, and a bolt .inserted to heoperated upon. e

Figure 2 is a longitudinal vertical section through the machine on the line y y, tig. 1, with a portion represented by dotted lines x x, fig. 1, removed from the socket and die-head.

Figure 3 is a longitudinal vertical` section through the center of themachine. i

Figure 4 is a .representation of the slidingframc, which holds the bolt to be threaded in place, as it is fed by the rotation of the dies and die-holder.

My invention relates'vto the construction of that class of machines for cutting screw-tlu'eads on bolts, &c., wherein the dies, when closed and in operation, are surrounded by a socket, so as to be held iirmly to their work until the screw' is cutofthe desiredlength, and then automatically opened, so as to release the screw-bolt and permit of its rapid withdrawal, without the necessity of reversing the motion ot' thedies or nnscrewing the bolt4 from the dies.' l

To enable others skillediin the art to use my improved machine, I will proceed to describe its construction and operation.

inthe severalfigures like letters of reference denote similar parts. 4

Ais the frame ot'` the machine, made of any desired shape, which will conveniently hold the several parts. l

A hollow cylindrical and horizontal shaft B is placed in suitable bearings in the pillar-blocks a c', which pillar-blocks rise up above the level of the shaft and support the shifting-bar C, which slides in grooves the top of thervpillar-blocks, being'kept in place by the caps b 1).

On the cylindrical shaft B, between the pillarblocks 'a a', is keyed the lgear-wheel D, which is revolved by a pinion, E, on the driving-shaft F.

G `isthe socket which' receives the die-head H, as

hereinafter described, the socket being a metallic'an nnlus, the cavity of which is exactly cylindrical, excepting that at the rear end are4 recesses c c c in the inner face of the ring, of sucient depth to receive the. projecting. tails t t t of the dic/holders when the dies are closed to their work, as will be ex plained in connection with the construction ofthe die holder. v

The socket G is placed so as to be concentric with the hollow shaft B, and is pivoted on each side at e c toa gimbal or ring, d.

The pivots e e, on which the socket is hung, are l not screwed into the socket G, but enter a groove, f, externally surroundingt-he socket, whereby the socket is not only pivoted to the ring (Z, but may be made to rotate on its axis,`within it. a

The gimbal or ringd is supported below in the frame of the machine by aforked projection, g, which engages -a small ange, h, on the hed of the machine, and above by a projection, gf, 'which enters a notch in the under side of the shift-infmlr bar C.

The two pivots e e are at the extremities of the` horizontaldiameter, and the projections g g' at the extremities of the vertical diameter of the socket G.

Fig. 3 represents the die-head H, which is a metallic frame, the exterior outline of which lis cylindrical, of same` diameter, and fitting closely into the cavity of the socket G. v

The die-head H has three recesses deep Venough to receive the three die-holders, I I I, which meet inthe center or axial -line of the die-head, in which lilies, at thel rear end of ihedie Il, is a cylindrical hole, tapped with a screw-thread, Vby which it is screwed onto the forward extremity ofthe cylindrical shaft B,

which enters'the socket G for that purpose.

When the die-head is placed inside ofthe socket G it lits snugly in it, but cannot turn round' therein, owing-to the tails tot' the die-holders I entering the recesses c c c of the socket, as before stated, so that, to screw the die-head on the lshaft B,'the socket is turned round with the die-headH.

The die-holders I are made to tit in the recesses in the die-head H, Vto which they are pivoted by a pin, i', at a'point below the cuttingcdges of the` screw-dies, so that, when thrown back, the dies are opened, and take no hold of the rod 'placed in them, but when closed they` are iu-a position to operate in screw-cnt# ting.

When thedie-holders 1 are closed, the tail-piece t of each die-holder I projects out beyond the outline ot the die-head H into its recess c, and the upper 'end of the die-holder is ush' with the edgeof the diihead; but when the dies are 'open the tail-pieces t ot' the die-holders I are withdrawn within the head H, and the upper end of the die-holders projects `beyond the circumference of the head. l 4

By this arrangement, in connection with the sliding of the. socket G forward or backward ou the head H, the opening and closing of the dies is accomplished. y

AAs the head H is screwed onto the shaftit revolves with it, but has no motion backward or forward, but

y the socket G maybe moved on the headH by means of the shifting -bar G. When thesocket G is moved forward on the head H as far as it will go, it closes the dies, the recesses G alloiviiig the tail-pieces t of the die-liolders I to project outward, and the socket hugging the upper end of the dies and the die-head so .closely as to keep the dies closed as rigidly as if they were not movable; when, however, the socket is slipped'a little back on the head H by the shifting bar, thedies are opened, the tail-pieces t being forced inward and t-lie upper end 'of the die-holders allowed to pass/outward.

Th dies N N YN, for cutting the screw-threads,'are

lmade lin the usual way, a-nd set in the die-holders I, and adj iistably secured thereto with set-screws y y, in the ordinary manner, as shown iii fig. 1.

The shaft B, which carries the die-liead H, is made hollow to 'receive the mandrel K, which operates the the bolt touches the adjustable end-piece k of thev mandrel K, and causes the dies to open and release the bolt from their bite. Therefore, by adjusting the length of the mandrel K by means of lthe end-piece 7.', the length ofthe screw to be out by theinaehineis regulated with the greatest exactness.

This release of the bolt from the bite of the dies is effected by the mandrel K, which, when touchedand pressed back by the end of'the bolt, comesin contact with and pushes back the vert-ical lever Z, vwhich is pivoted at its lowerl extremity tov the frame of the macliiue, w'hiie its upper. end enters a sloti the outer extremity of the shifting bar C.

'llie upper end of the leven l is beveled, so as, when pressed back, to i'aise the latch lm, which is hinged to the top of the rear pillar-block a', and the hooked end of which engages the end of the shifting bar O, and keeps it pressed forward; when the shifting bar is lin this position (the latch m being set) the gimbal or ring d -is pressed forwai'd, and the socket G is forced up on the die-head H, so as to close and hohl fast the dies.

As soon, however, as the mandrel K touches the lever l, lthelatch m is raised and releases the shifting bar C, which ls pressed a little backward bythe spring s on the'p'illar-block a, bearing against the pin o on the shifting bai'.

On the sluiting bar C is a beveled projection, u, which reaches downward over the gear-wheel D, not quite touching it, and on one side of the gear-wlieel l) is a corresponding beveled projection, c, reaching upward, so as to engage the projection 'a of the shifting bar when the latch m is caught on the end of the shifting bai', holding itforward, the plane surfaces of the two projections lu and o pass eachother withont interfering, but as soon as the shifting bar is pressed a little back by the spring s, on. releasing the latch m the knife-edges of the beveled projections n and fu meet on their beveled faces, and, vas they pass each other, they force the shifting bar back suiicient-ly to drawthe socket Gon the die-head H, which leases as before stated, opens the dies and frees the bolt on which the screw is being cut, which can be iminediately withdrawn.

The bolt to be operated upon is secured in a sliding frame, L, in such a manner as to be in the axial line of the die-head H. This sliding frameL maybe made in any convenient manner, so as to hold the bolt firmly, and slides freely on horizontal ways n a on opposite sides of the frame ot' the machinei In the sliding fraaie L is bolted aplate, p, havinga hole, 0,-(see iig. 4,) of sucient size to receive the shank ofthe bolt, but not allow the head to pass through.V 's' In front of and parallel to this plate is pivoted-'ian yarm, q, whichvsliuts down against the head ofthe bolt,

and a set-screw, w, in the arin q, is screwed downA on tothe head ot' the bolt, which holds it rigidly in position.

The operation of my machine is as follows:

The bolt x, to be threaded, being set, as j ust described, in the frame L,the shifting bar O being drawn forward so as to draw the socket Gr over the die-head H, ciose the dies,and the latch m being rset, the frame L is pushed forward unt-il the bolt :c enters the bitcof the dies N N N.

As the die-head H revolves-with the shaft B, a screw is cut on the boltfwhich is drawn in between the dies by their action in cutting. This operation continues until the end of the bolt a: touches the forward extremity of the mandrel K,.and presses it back until it touches the lever l, which raises the latch in and releases t-lie shifting bar O.

. The beveled projections u and fr, in the bar G and gear-wlieel D then interfere and push back the shifting bar G far enough t'o withdraw the socket G land open the dies N N N.

The threaded bolt a: being then free, the sliding frame is then drawn back and the boltx removed, and another bolt inserted in its place,

Having thus described my machine, v

TWhat I claim as my invention, and desire to seciii'e by Letters Patent, is

1. 'llie form of construction, herein described and shown, ofthe inner surface oft-he sliding socketG,ai1d

of the upper edge of th'c pivoted' holders I, and the arv rangement of theni in relation to each other and to the die-head H, in virtue of which the diesare opened oni'etracting the socket, and 'forced toward eachother and held firmly in position on the forward movement of the socket, substantially as set forth.

2. The con'ibination, with the mandrel K, dies, dieliolder, and socket G, of the ring d, supported below on ange h, pivoted at the middle to the socket G,

and connected at the top with the bar C, or its equivalent, through the medium of which, and other suitable iiiecliaiiisin, the force exerted by the bolt-blaiik on mandrel K is communicated to said ring and socket, substantially as described.

3. The socket for inclosng t-lie die-holders, and the ring d, in combination with shifting bar. C, mandrel K, lever L, and beveled projections u c, substantiallyI as set forth,

In testimony whereof, I, the said EDWARD KAY- LoR, have hereunto set my hand.

'r EDWARD KAYLOR.

Witnessesr l A. S. NIoHoLsox,

Trios. B. Keita. 

